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To understand how Samsung -- yes, Samsung -- became America's No. 1 mobile phonemaker and thorn in Apple's side, it's helpful to rewind to last fall. On a mid-September morning, Apple (AAPL) CEO Tim Cook stepped onto a stage in San Francisco to unveil the iPhone 5. Several hundred miles away, in a Wolfgang Puck restaurant in Los Angeles, a group of marketing executives from Samsung Electronics followed real-time reactions to Cook's remarks. They huddled around tables mounted with laptops and TV screens, carefully tracking each new feature and monitoring the gush of online comments on the new device via blogs and social media sites. As the data flowed in, writers from the company's advertising agency, who were also camped out in the restaurant turned war room, scrambled to craft a...